问一道SAT 语法题?

题目

问一道SAT 语法题?
singer quickly patented the sewing machine he had invented,eunsuring that he would profit form its commercial success
为什么 ,ensuring himself to profit form its commercial success 不对?

答案

这里代词没有错,那只可能有错的就是搭配了
ensure that...应该是固定的句式
ensure sb sth固定搭配
我查了google,没有发现有ensure to do这种句子